Manufacture of wire



Patented Aug. 15, 1939 UNITED STATES PATENT OFFlCE tional StandardCompany, Niles, Micln,

poration of Michigan No Drawing. Application September 22, 1937, SerialNo. 165,075

Claims.

This invention relates to the drawing of wire, and has for an object theeffective lubrication of the wire as it passes through a die.

In drawing wire it is very important to pro- 5 duce a lubricatingcoating on the surface of the wire to separate the wire from the surfaceof the die during the drawing operation, both to secure a good productand to protect the die against undue wear. One commonly used lubricantis powdered soap, usually placed in a box through which the wire isdrawn just before it enters the die. If the surface of the wire isfairly rough, ample powdered lubricant is carried by the wire into thedie. Sometimes the roughness is increased by slightly rusting the wire(so-called sullin.g), but with stainless steel wire (i. e. wire of analloy containing a considerable amount of chromium) this is notfeasible, and other lubricating methods have heretofore been resortedto.

The present invention aims to insure that the wire will pick up adequatelubricant, by providing a rough surface on the wire by other means thanrusting, and preferably by precipitating crystals on the surface of thewire before it passes into the lubricating material on its way to thedie. The crystals may be formed by passing the stainless steel, or otherwire material being drawn after pickling and cleaning,

through a hot saturated salt solution, for example of sodium chloride,soda, or a mixture of sodium chloride and soda, or of equivalent saltswhich are 'not expensive and which crystalize readily from saturatedsolutions, or one of the more easily crystallizable sugars (as forexample ordinary cane or beet sugar).

After immersing the wire material in this solution it is withdrawn anddried by evaporating oil the water or other solvent slowly enough toleave a rough surface covered with adherent crystals. It is then furtherpassed in the usual way through a mass of powdered soap, or otherlubricant, directly into the die. Preferably the lubricant is agitated,or the wire is moved -through itin a non-uniform manner, to preventcaking of the lubricant. While the invention is of especial value indrawing steel wire, it is not my interption to limit the invention tothe manufacture of wire of stainless steel only, or otherwise than bythe terms of the appended claims.

I claim:

1. That method of making wire which com- 5 prises passing the wire to bedrawn through a substantially saturated solution of a crystallizablematerial, evaporating off the. solvent to leave crystals of saidmaterial on the surface of the wire, then passing the crystal-coveredwire 10 through a body of powdered lubricant'such as soap and thendrawing the wire through a die.

2. That method of drawing polished stainless steel wire which comprisespassing the wire to be drawn through a substantially saturated 15solution of a salt, evaporating oil the solvent to leave salt crystalson the surface of the wire, then passing the crystal-covered wirethrougha body of powdered lubricant such as soap, and then drawing the wirethrough a die.

3. That method of drawing polished stainless steel wire which comprisespassing the wire to be drawn through a substantially saturated solutioncomprising soda and sodium chloride, evaporating off the solvent toleave soda and 25 sodium chloride crystals on the surface of the wire,then passing the crystal-covered wire through a body of powderedlubricant such as soap, and then drawing the wire through a die.

4. That method of drawing polished stainless 30 steel wire whichcomprises passing the wire to be drawn through a substantially saturatedsolution of sugar evaporating oil the solvent to leave sugar crystals onthe surface of the wire, then passing the crystal-covered wire through abody 35 of powdered lubricant such as soap, and then drawing the wirethrough a die.

5. That method of making polished stainless steel wirewhlch comprisespassing the wire to be drawn through a substantially saturated 'solu- 40tion of a crystallizable material, evaporating off the solvent to leavecrystals of said material on the surface of the wire, then passing thecrystalcovered wire through a body of powdered lubricant such as soapand then drawing the wire 45 through a die.

AKE DAHLBERG.

